Airbnb exclusively told the Thomson Reuters Foundation that it has teamed up with anti-trafficking charity Polaris to train its employees, develop new systems and work with the police to spot signs of slavery and prevent people from being trafficked.

The nonprofit organization she joined in 2015, Airline Ambassadors International, trains workers at airlines and airports how to spot, and report, cases of human trafficking. It also delivers humanitarian aid around the world and transports sick children who need medical care.

A teenage girl uses cash to rent a room with an older man. A housekeeper, who appears to be living on site, nervously averts eye contact when a guest approaches. A string of men enter and leave a particular room throughout the night, each staying for only 30 minutes at a time.